Revert the change of the requirement of reflection-docblock

Revert the change of the requirement of phpdocumentor/reflection-docblock in composer.json

Author: fiboknacky

composer.json

@@ -9,7 +9,7 @@
     "guzzlehttp/guzzle": "^6.0",
     "guzzlehttp/psr7": "^1.2",
     "monolog/monolog": "^1.17.1",
-    "phpdocumentor/reflection-docblock": "^3.0.3",
+    "phpdocumentor/reflection-docblock": "^4.0.0 || ^3.0.3",
     "symfony/serializer": "^2.8.0 || ^3.0.3"
   },
   "require-dev": {